Vacuum flasks



Sept. 19, 1961 L. LESLIE-SMITH 3,600,525

VACUUM FLASKS Filed Feb. 16, 1959 FIG.2

INVENTOR [au ra vce [esZe Sm/77b ATTOENEY-s 3,000,525 VACUUM FLASKSLaurance Leslie-Smith, Grosvenor Gardens House, Grosvenor Gardens,London SW. 1, England Filed Feb. 16, 1959, Ser. No. 793,605 Claimspriority, application Great Britain Feb. 14, 1958 4 Claims. (Cl. 215-13)The present invention relates to vacuum flasks and like containers wherethe actual container for the liquid or other material to be received ishoused within an outer canister or like casing.

In the specification accompanying copending application Number 706,321there is described and claimed a screw stopper assembly for a vacuumflask the screw stopper being threaded into a pouring lip which servesalso to position the top of the flask bottle in the casing in such amanner that relative movement is permitted to allow a bung portiondepending from the threaded portion of the stopper to align itself inthe neck of the flask bottle.

An object of the present invention is to provide a screw stopperprimarily for a vacuum flask in which no intermediate pouring lip isemployed.

A vacuum flask normally consists of an outer canister comprising a lowercylindrical portion having on its upper end a shoulder portion made ofmetal or some other rigid material which shoulder portion screws ontothe canister. Heretotore this shoulder portion serves only to positionthe flask bottle at its upper end and to receive a screw-on cup. In onesuch known construction the screw-on cup presses down upon a separatestopper which is first inserted into th evacuum flask bottle. In such aconstruction the flask bottle is mounted substantially rigidly in thecanister and has relatively no freedom of lateral movement.

It is not possible to provide the actual screw means in the glass of thebottle itself because of the nature of the flask bottle and its methodof manufacture.

According to the present invention a vacuum flask comprises an outercanister which includes a shoulder portion, a vacuum flask bottle housedwithin the canister and located on support means in the base of thecanister, a resilient annular sealing member between the neck of thebottle and the inside of the shoulder, and a stopper provided with screwthreads which engage screw threads on the shoulder and including a bungportion depending from the threaded portion of the stopper so as toextend into the neck of the bottle when the stopper is screwed home ontothe shoulder said annular member being such as to allow lateraladjustment of the neck,

This integral assembly of a screw stopper and a bung is possible becauseof the resilient sealing member which in addition to maintaining a sealbetween the neck of the bottle and the inside surface oi the shoulderalso permits the bottle to move laterally so as to align the neck withthe bung to provide a seal for the bottle. This lateral movement isnecessary because of the variation in the neck contours between thebottles caused by the forming and moulding processes.

The shoulder may, if desired, be made from an artificial resin such aspolyethylene so as to provide a certain amount of resilience andflexibility. Alternatively, the shoulder may be made of metal in thenormal manner screw threads being pressed into the metal during themanufacturing operation. Inside the shoulder either in the neck portionor lower down there may be provided an annular member made of resilientmaterial, for example rubber or synthetic rubber, which is secured byany convenient means inside the shoulder and positioned and shaped sothat it engages the outer portion of the lip of nite States Patent C)ice the neck of the vacuum flask, the annular member being of suchdimensions that it allows the flask a certain degree of lateraladjustment and also provides a liquid seal between the flask bottle andthe shoulder.

The invention will now be described with reference to the accompanyingdrawings in which:

FIGURE 1 shows a vacuum flask in accordance with the present invention;

FIGURE 2 shows on a larger scale and in cross section details of theupper portion of one construction in accordance with the presentinvention;

FIGURE 3 shows a similar view of a further construction; and

FIGURE 4 shows yet a further construction.

Referring to FIGURES l and 2 the vacuum flask comprises a metal canister1 provided with a screw-on shoulder portion 2 which is provided withthreads 3 to receive a cup 4. Referring more particularly to FIGURE 2the canister shoulder 2 is provided with a cylindrical upper portion 5upon the inside of which is formed screw threading 6.

The vacuum flask bottle 7 housed within the canister is located in theupper portion of the canister by means of a resilient annular sealingmember 8 which lies in the bulge in the shoulder beneath the screwthreading 6 and is so shaped as to provide a liquid seal between thebottle 7 and the shoulder 2 to allow the contents of the bottle to bepoured out without any leaking between the bottle and the canister.

The stopper 9 has provided about its upper portion screw threads 10which mate with the threads 6 on the inside of the neck of the shoulder2. The stopper 9 also has a depending portion 11 which when the stopperis screwed home enters the neck of the bottle 7 to act as the main sealto the contents.

Conveniently the stopper 9 is also provided with an annular flange 12which overlaps the rim of the shoulder 2 against which it bears to forma secondary seal.

The stopper may be formed of a plastic material and at least the bungportion may have a degree of resilience. As shown in the drawing thestopper is hollow and may be constructed in accordance with my oopendingapplication Number 706,321.

In spite of the irregularities in the necks of vacuum flask bottlesbrought about by the process of moulding and forming the neck, the bungwhen it enters the neck of the bottle forces the bottle against theresilient ring in one direction or the other so that the neck is alignedwith the bung and so the bung enters truly into the neck and forms aseal. The resilience of the bung itself Serves to take up any internalirregularities on the face of the neck of the bottle.

In the embodiment shown in FIGURE '3 the screw threading 6 on theshoulder 2 is formed on the outside and the stopper 9 has screw threadsformed on a depend ing peripheral flange 13. The resilient sealingmember 8 is located substantially in the same position. This formerconstruction allows for a free flow of liquid from the bottle over asmooth surface without having to pass over screw threads. In this casethe bung portion 11 extends from the top of the stopper into the neck ofthe flask bottle.

In the construction shown in FIGURE 4 the neck of the flask bottle 7'extends into the neck 5 of the shoulder 2. In this case the annularsealing ring 8 is positioned in the upper portion of the neck of theshoulder and is contained beneath an inwardly turned rim 14 formed onthe neck of the shoulder with the lip of the flask bottle lying beneaththis rim and snugly against the sealing ring.

The screw threading 6 is formed upon the outside of the neck of theshoulder of the canister and the screw thread on the stopper is formedupon the inside face of the depending flange as described with respectto FIGURE 3. v

The connection between the depending flange on the stopper and the bungportion 11 is so contoured as to match that of the rim 14 to form asecondary seal for the flask.

In the construction shown in FIGURES 2 and 3 the lip of the neck of theshoulder of the flask can be shaped to form a pouring lip and so beprovided With an upper bevelled edge which also serves, when the screwstopper is applied, to bite against the inside of the rim of the stopperto serve as a seal.

Whilst in the constructions of the invention illustrated the sealingmember is shown as an annular ring engaging the top of the neck of theflask the sealing member may if desired be applied lower down the neckor upper portion of the vacuum bottle. This sealing member may be anindependent member which can be slipped onto the neck of the flask or itmay be secured to or formed integrally with the inside face of theshoulder. Thus in the case of the shoulder being formed from anartificial resin the shoulder can be formed integrally with a dependingflange or flanges which either engage the flask directly or engageagainst the annular member secured to the flask toprovide a location forthe flask and to provide means to permit the flask to move laterally toalign itself with the bung when the stopper is applied.

What I claim is:

1. A vacuum flask comprising a canister, a base closing one end of thecanister, a shoulder portion on the other end of the canister, a vacuumflask bottle housed within the canister between said base and saidshoulder portion, a neck on said bottle, a resilient annular sealingmember surrounding the neck and engaging the shoulder portion, anupstanding cylindrical portion on said shoulder portion, screw threadson said cylindrical portion, and a stopper having a depending bungportion for engaging in the neck of the bottle, a cylindrical portion ofsubstantial axial length on said stopper, and screw threads on saidcylindrical portion of the stopper for engaging the screw threads onsaid upstanding cylindrical portion whereby when the stopper is screwedon to the shoulder the bung portion is urged into the neck of the bottleuntil it fits tightly therein to form a closure therefor, the saidresilient sealing member permitting lateral displacement 4 of the neckof the bottle for receiving the bung portion of the stopper.

2. A vacuum flask as claimed in claim 1 wherein the upstandingcylindrical portion of the shoulder is provided on its inside face withscrew threads which mate with screw threads upon the'outside face of thecylindrical portion of the stopper and wherein the top of the vacuumflask bottle lies beneath the threads on the shoulder.

3. A vacuum flask as claimed in claim 1 wherein the upstandingcylindrical portion of the shoulder is provided with screw threads uponthe outside face thereof to engage threads provided upon the inside faceof a depending cylindrical flange portion on the screw stopper, the topof the vacuum bottle lying beneath the said cylindrical portion of theshoulder.

4. A vacuum flask comprising a canister, a base closing one end of thecanister, a shoulder portion on the other end of the canister, a vacuumflask bottle housed within the canister between said base and saidshoulder portion, an upstanding cylindrical portion, a neck on saidbottle extending into the said cylindrical portion, a resilient annularsealing member surrounding the neck and engaging the said cylindricalportion and lying between the neck and the cylindrical portion, screwthreads provided on the outside of said cylindrical portion, a stopperhaving a depending bung portion for sealingly engaging in the neck ofthe bottle, a depending flange upon the rim of the stopper, and screwthreads provided on the inside face of the said depending flange forengaging the Screw threads on the outside of the cylindrical portion ofthe shoulder, whereby when the stopper is screwed onto the shoulder, thebung portion extends into the neck of the bottle to form a closuretherefor, the said resilient sealing member permitting lateraldisplacement of the neck of the bottle for receiving the bung portion ofthe stopper.

References Cited in the file of this patent UNITED STATES PATENTS2,815,879 Hermes Dec. 10, 1957 2,830,722 Darrnstadt Apr. 15, 1958FOREIGN PATENTS 765,063 Great Britain Jan. 2, 1957

